Railway traffic controlling apparatus



Jfc. LAW 2,404,303

Filed June lO, 1944 8 She-etsSheet 1 INVENTOR d 2. 2 a @IFAC M .Jpl A h@ M w .9u .b/:: -w .M ,M -l ---W QW a `5 m M5 d imm.: E fn Q a L Tel d e y 9 m .L T 0 4c d UW, a .WMI vlQeL, E v W M, 1J @im C W :1.a !,.a.:..-i| E? i A 2. a o |.b e A m me 254.5607; 7. A d

July 16, 1946.

I YHZ A 4HISATTORNEYv J. C. LAW

RAILWAY TRAFFIC CNTROLLING APPARATUS Filed June 10, 1944 July 16, 1946.

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RAILWAY TRAFFIC CONTROLLING APPARATUS INVENTOR .fo/12 Cap! [aa/ July 16, 1946.

J. L Aw RAILWAY TRAFFIC CONTROLLI-NG APPARATUS Filed June 10j, 1944 8 Sheets-Sheet 4 2M? 25AM? i John @arl [aw maar HIJMTTORNEY ZZAPC bl ai JJ E/PZ) N- IW? [ZH July 16, 1946. J, c. LAW 2,404,303

RAILWAY TRAFFIC CONTROLLING APPARATUS ,Filed June l0, 1944 8 Sheets-Sheet 5 A T i (.7 HIJATTORNEY July 16, 1946. .lA LAW 2,404,303

RAILWAY TRAFFIC CONTROLLING APPARATUS- Filed June 10, 1944 8 Sheets-Sheet 6 a '-H i 25E l I Q@ 24K 77 75l/Vl E 44 C f6' 50 45 1 46 i WAR im my 5W lin-wa 7 e 45 47% i Aj Hg. 2z?.

II\AVIVNTOR 7o/212 czz?! [aw @Ya/1m HIJ ATTORNEY July 16, 1946. J c, LAW 2,404`,303v

RAILWAY TRAFFIC CONTROLLING `APPARATUS Filed' June 10, 1944 8 Sheets-Sheet 8 WLF 43,45 e my @f d d I LZ INVENTOR J/in p( [oral 4 BY @@Lloa WZ) 2 t HIPATTORNEY Patented July 16, 4194e UNITED STATES PATENT orifice RAILWAY TRAFFIC ooNTRoLLlNG i APPARATUS John Carl Law, Topeka, Kans., asfsfigioruto rThe Uilion -Switch and Signal Company, 'Swis'svala Tal, afcorporation of Pennsylvania 4 Application `J une 410, 1944, Serial No. 339,619

(ol. 24e-3) 15 Claims.

My invention relates to railway tiailic controlling apparatus, and more particularly 4to acentralized trailic control system for governing train movements over a single track railway.

My invention contemplates the provision 'of power operated track switches at various lojcations to give access to suitably fsp'aced passing sidings, lt'ogetller with an absolutey permissive .block system having 'automatic signals at spaced locations in the single trackv stretches, and with lmanually controllable head block signals at the power switch locations, `fr governing traflic movements in both 'directions YThe signals are governed 'automatically in accordance with ltraiiic conditions over a manually 'reversible line circuit system employingbut 'two line wires and c'ontrolled bythe track relays of various track se'c tions, continuous track circuits being provided for all main track, and also 'for the passing tracks.

The 'System of my "invention is provided with a suitable communication system,l preferably of the impulse code type, having a station codingu'nit at each of a plurality `of stations each of which comprises a power switch location. Each such coding unit provides means 'for manually con'- trolling the track switch and the adjacent head block signals, for both directions, vfrom a central point such vas a train 'dispatchers olic'e, and for controlling the reversible line circuit system to set up the desired vdirectitwl for 'traiic movements in the adjoining blocks. The communication system serves alsoto indicate the condition of the track switches 'and headblock signals "at the con: trol o'lice, and further, toindicate the presence of al trainat any point in the controlled territory by the lighting of suitable lamps 'on a track diagram at the office, the diagramcontaining a lamp for each detector section including a power opfer-v ated track Switch, a `lalrlp foreach single track stretch, and lamps for the main and passing tracks of the double track portions.

A feature of my yinven'tii'ili the provision of electrically interlocke'd 'circuits atthe ,control of; lice for governing the reversible linecircuit system. In respect to this feature, in'y invention an improvement upon that disclosedina pending application for Letters Patent of the United states, serial i o, 501,254, olea seotoiiiloe're, 1943, oytlenry s. Young, for Railway traino oontrolling apparatus. I

As' herein disclosed, the apparatus at the con-` trol oiiice includes a series of directional relays, 'one Ifor each block, each l" which governs the transmission of codes 'for'.controlling` the direction of trallio to'be set up in its block, by' control:

ling the direction of 'energizatio'n of the y ,A sponding portion of the line circuit Vsyst `rn. Whereas in the Y` ung system directional control is provided only 'for the single track blocks, in the system of my invention itis exteiided to ln'- clude all main "track, The communicationfsys 'teni includes the usual code starting push bute tons yflor 'initiating code transmission, one :for 'each station corresponding to a power switch lo; cation, and the control of the trafc direction 'each block is governedA in a novel manner tn; eiation of oneor vthe 'other of the 'two starting buttons for the lstations at 'the 'oppositeexids yof the block, depending upon the direction to be $915 uit, i

one object y'ofmy invention is' the provisit improved circuits rfor electrically interlocking 4a remotely controlled 'power 'operatedtiaokswiten and the signals. which govern trailic movements over the switch, which includes, means Kfor pre? ventingthe incorrect routing of a train the result of the transmission "of codes for A"per 'ig 'the track switch and for clearing a signal when the switch assumes a new position, which islet-j fective in the` event the switch is electricallir locked and thereby lprevented from responding totheco'de. i, Y ,l 'f y y vAnother 'object of my invention is the prtgv l of improved arrangements for the control of t ,cjA tric switch lockst The railway sy tems to which my invention is applicable include i numerous switches giving access to the main track yvl'lliic'lh are intended primarily for operation by the ws of trains doing local switching, such as thos f leading to industrial sidings or the like "or to adi ditional passing tracks used but infrequently, for which they provision of power switch machines is unwarranted, but for which locking is required for the protection of main line trainl movements; In such cases the'track switch is preferably oper; ated by a hand throw mechanism having its op erating lever locked in its normal position an electric lock adapted 17o/be released by energizing a magnet My invention includes improved ci`4rl cuits for controlling such electric locks, includi time control means controlled lby an approac iig d main line train for enabling the 'switch to be unev locked to permit the train to enter theside track, together with means controllable by the central office operator for distinctively controlling the reversible line ycircuit system for the block con'-vv taining the hand throw switch, to enable the switch'to be unlocked for a movemeritout of the side track, provided'rio train is approaching from either direction. In' respect to this feature, myrv Referring to the accompanying drawings, Figs.

1A and 1B, taken together, illustrate,- two adjacent panels of a control board located at a central office and arranged for the centralized control of the trackway apparatus of myjnvention, ,y

the later being shown in Figs.v 2A to 2F, inclusive.

It is to be understood that the control `board-in-y its entirety comprises a number of such panels, alternate panels being generally similar to Fig. 1A `and the intervening panels to Fig. 1B.

Figs.' 1A and 1B, taken together, with Fig. 1A at the left, show the'oflicev circuits for the controlof atypical single track block, suchras` is illustrated bythe miniature track diagram shown thereon.Y This block extends from a head block signal 2BA or 2RB, at the left-hand end of the detector track scctionfor the power operated track switchv IW, through the single track stretch to the Yopposing head block signal 4LA Vor 4LB, at the right-hand end of the detector track section for a similar switch 3W. The track diagram alsoshows a Vnumber of electrically locked hand throw switches in various typical locations .designated SAW, SBW, 'IW and 9W, respectively.

Figs.' 2A to 2F,'inclusive, arranged side by side withy Fig. 2A at the left, show the track plan and circuits associated with ythe single track block. Figs. f2A and 2B taken together show the local ,circuitsv forV switch IW, located in the detector track section IT, 'and for the adjacent head block signals ZRA, 2RB and 2L. This group of trafi'icgoverning devices is manually" governed from the oflce'by the operation of a coding unit des- A 4ig'nated Station No. I,-shown in Fig.. 2A..

Fig. 2C shows the local circuits for a typical pair of automatic signals identified by the reference' characters 2l and 22 and located within the single track stretch. Fig. 2D shows circuits .50

Yfor similar signals 23 and 24 at a second location within Vthe stretch. Figs. 2E and 2F, taken together, show the circuits for the control of a group of devices corresponding to those of Figs. y2A and 2B, comprising the power operated track switch 3W located in a detector track section 3T, and the associated head block signals 4R, 4LA and' 4LB, which group of devices is manually governed from the oice bythe operation of a coding unitA designated Station No. 2, shown in Fig. i Y A y Y lThe circuits for controlling the electric locks for the hand throw switches vary in some respects in accordance with the location of the switch with 'respect to the signals, and accordingly a numberofcircuit arrangements are shown tor illustrate different situations. These include circuits for two handthrow switches designated SAW and 5BW,'located at diierent points in an intermediate block sectionof the single track stretch and arranged to provide an additional passingftrack for emergency use,and also in'- clude a switch IW located in-an end section of the single track stretch and a switch 9W located in the main track of the double track stretch.

5 a passing siding. When Fig. 1A is placed at the right of Fig. 1B, these views together show the track diagram for the block. having the signals 4R and 2L at its opposite ends, and also show theV cnice circuits for the control'cf these signals in l0. connected form.

The track plan and trackway circuits for the [signals dR'and 2L controlling movements intoY the passing tracks may be similarly shown in connected-form, together with the circuits for I5 their respective'approach' sections, by arranging Figs. 2A-2F vside by side in the order 2D, 2E, 2F, l2A, 2B, 2C. 'I'he main track block extends from 'signal 4R., at its left-hand end, through sections 3T, IlLAT, ZRAT and IT to signal 2L.

2o Sections 4LBT and 2RBT are also provided with track circuits which serve to indicate the occupancy of the, passing track by the lighting of a lamp on the" track diagram of Fig. 1B, and also provide approach lighting control for signals 5 ALB and 2RB.

Similar reference characters refer to similar parts in each of the several views.

The code system employed for communication between the oice and stations may be lof any suitable type, and as a consideration of its detailed mode of operation ,is not needed for an understanding of my invention, this is illustrated herein only in diagrammatic form. Asshown herein it is assumed that this comprises the re- 25 mote control systemof LettersPatent of the United States No. 2,197,130, issued April 16, 1940, to Lloyd Vf Lewis, having coding units at the office and at the several field stations connected by line wires Y-Z as indicated diagrammatically 40 on the drawings, over which control codes are transmitted at times from the office to a selected station to position a group of'polar stickcontrol relays at that station, while at other times indication codes are transmitted over the same line wires from the different stations, one station at a time, to position a group of indication stick relays associated with an invidiual control panel for the station transmitting the code.

It is to be understood that each such code includes a distinctive combination of elements for selecting the desired station and the corresponding oiice panel to temporarily establish a group `of seven channels .for communication Vbetween such station and panel. For simplicity the channels are indicated conventionally on the drawings as individual circuits, the control channels being represented by a group of wires I-1, and the indication channels-by another group of wires 9-15, each adapted to be'energized from the positive or supply terminal B of asuitable local source of current at one end and having a connection to the negative or common return terminal c of such source at the other end. 'Channel 6 is not used in connection with my invention and is not shown.

Each control code is initiated manually, by momentarily operating a starting push button, after placing the control levers ofthe panel in the desired vpcsiitions.y Fig. 1A showsthe con- 7o trol'panel for the control ofthe track switch relay OI S and therebyextends thel channels I?? arcanos r `if', *from vthe office to :Station No. I, Fig. 2A', to :ene-rgize selected register relays .'IFZ, IF4, letc., in icludedin certain of the channels. A-t the :end of thiscontrol code, a delivery relay ID ismomen-Y tarily energized, thereby position'ing'varicus stick polar control relays to normal or reverse in acordance with the condition of energization of Linne channels. It is to be understood Ythat as shown herein the normal position of each polar- :ized relay is taken :as .the left-hand position and that ."lt :closes its normal or left-hand vcontacts fwhencurrent 'from terminal B ilows Afrom left xtorightthroug'h its winding to .terminal C, and that :it closes its right-hand or reverse contacts when theow vof current vfrom terminal B through its winding is from `right .to left. The stick polar control relays at Station No. I include a switch control :relay IWS and an vauxiliary relay 'IWIS,V

voperable to'norm'alor reverse over channel I or '.3 in accordance with the position of the vswitch. ,liever ilSW, Fig. 1A, 'two signal control 'relays LHS land .2RHS, operated to reverse over channel or `I when the signal lever yZSGr of Fig. 1A is placed in its left-hand or right-hand reverse position, respectively, and to normal when lever '.ZSG is placed in its normal center position, and two .traic .relays ZRFS and 2LFS controlled over .channels v2 and 4. Relay ZRFS is controlled by a directional relay 2--4LP of the stick polar type, .shown in Fig. 1A, the position of which designaites the Adirection -for trafhc movements-into the `ablock, contact a of relay `2--IILP controlling direction :indicating lamps WFE and .EFE Vmounted .belowfthe `track diagram. Relay ZLFSis controlled by the directional relay 4-2LP located in the 1adjoining panel `at the left of Fig. 1A. Fig. 1B shows the control panel for the switch 3W and the signals rat 'Station No. 2. The operation,

lof :the starting button 2STB shown in this view .energizes'a :starting relay .2ST and a selector relay 02S, thereby extending channels I-I to Station JN0. 2, to energize the register relays 2F2, z2F.4, etc. rAt the ends of each control code delivered by relay 02S a delivery relay 2D is momentarily energized to operate the polar stick control relays of Fig. 2E to normal or reverse in accordance with `the condition of energization of channels lI-'I. The switch control relays SWS and SWIS are controlled in accordance with the position ofthe switch lever 3SW, and the signal control relays 4LHS and IIRHS in accordance with the position of the signal lever IISG. The trahie relay ARFS is controlled by the directional relay A-ZLP shown in Fig. 1B and Vrelay ALFS bythe similar relay 2-4LP of the adjoining panel at the left.

.It is to be understood that each station coding unit is arranged to initiate an indication code in :response to each change in position of any of the indicating relays which govern the energization of channels 9--I5 and also in response to a .received control code, even if no such change occurs. Each code initiated at Station No. I causes the energization of a selector relay IS, Fig. 2A, and at the end of such code a delivery relay OID, Fig. 1A, is momentarily energized, causing the associated indication relays K to assume energized or released positions in accordance ywith the condition of energization of channels A9--I5.

Relays INWK and IRWK are controlled over channels 9 and I I by the switch indication relays INWP and IRWP, Fig. 2B, which reflect the position of switch IW, and serve to light lamp INE or IRE to indicate the position of switch 6 Relays fZlLiHK and ZRHKmelcontrolled over ichannels lf3 and I5 bythe signal 'indication relays IZLGP 'and 2RGP 'so `as to light lamp ZINE Vwhen 'the signals at Station NoI yare at `st'op,'to light lamp .2LE when signal 2L is cleared, andtolight lamp 2RE when signal ZRA or ZRB is'V cleared.

Indication codes initiated. at Station No. 2 cause the energization of the :selector relay 2S, Fig. 12E and ofthe delivery vrelay 02D, Fig. 1B,fto eilect a similar control, over channels Y9, II, I3 .fand I5, of the lamps Aassociated with levers 3SW and ASG in accordance'with the condition 4o'f switch 3W and of 'signals 4LA,"4LB and 4R.'

The :remaining indication stick ,relays 'of Figs. .iA and :1B ycontrol the lamps .of the track diagram in such a manner as to `continuously indicate 'the .presence of ar train 'by the lighting of one lor `more lamps, wherever the. train may be in the controlled territory. Relays ITK and 3TK control the lamps ITKE and 3TKE, land are controlled over channel I0 fbyrepeating relays `ITP and -STP of the track relays for 'the detector track sections IT and 3T, in the usual manner.

The block indication relay ZLAK, Fig. 1A, and lrelay TARAK, in Fig. y1B `at the right jointly cause lamp BKE to be .lighted t0 indicate the presence of a 'train in the `single track stretch, and are controlled over channel I2 by approach relays Z'LAR ;and 'f4RAR, respectively. Relay '.2LAR, shown .in Fig. 2B, is `controlled over a circuit extending from one terminal B of a ,local source :of current at front contact e of the track relay y22TH, Fig. 2C, over back contact c vof :a directional stick relay 22SR, which as hereinafter described, is energized when a trainfmoving 'from left to right occupies section 22T or 23T, and over 'contact a of the track relay 2ITR, wire I8, lcontact a of the track relay ZLATR, through 'the winding of relay ZLAR, and 'over contact c -of relay ZLATR, and line wire I'I to terminal C of `.the saine-source at contact c of relay 2 ITR.

Relay IRAR, shown in Fig. 2E, is controlled over asimilar circuit including line wires I9 and '.20 and the .front contacts-of the track relays 4RATR, 24TR and 23TR, its circuit alsoincluding a back contact of a directional stick relay 23SR which is energized when a train moving from right to left occupies section 23T or 22T.

The block indication relay 2RAK, Fig. 1A, controls va block indicator lamp ZRAE in the track diagram of the adjoining panel at 'the left, to indicate the occupancy of the main track of the `double track stretch. Relay 2RAK .is controlled over `channel I4 by relay 2RAAR, Fig. 2A, which vin turn :is controlled by `a signal lighting. relay 2RAER in series in the reversible line circuit including line wires 39 and 40, hereinafter Idescribed. Since this line circuit includes vfront contacts b and d of the track relays 2RATR Aand, IlLA'IR, relay ZRAAR reflects the condition of track sections ZRAT and IILAT.

-The block indication relay 4LAK, Fig. 1B, controls lamp IILAE to indicate the presence of. a train in the upper passing vtrack of the double 'track stretch. Relay 4LAK is controlled vover 'channel I4 from Station No. 2 by relay IILBAR, shown in Fig. 2F, which relay is energized over line wires 29 and 30, and front contacts a and b of the track relays 4LBTR and 2RBTR from terminals B and 'C of thev local source at Station No. I. 1

The polar stick relay 2-4LP, in Fig. 1A, `serves as a directional relay for Vcontrolling the direction 4of 'trallic vmovements in the single track block and controls the traffic relays SZRFSand to `Station No. I or No. 2.

7 4LFS, which govern the reversible linecircuit system for the-single track stretch, by the operation of its contact c, which controls', the energization of channel v2` in each control. code transmitted Relays ZRFK and 4LFK in Fig. 1A are slow release directional stick relays controlled byl relay 2`4LP and by lthe 4block indication relays ZL'AK of the same panel and 4RAK of the nextrpanel at the right.v Relay ZRFK or vILFK picks up over contact b of relay 2--4LP inv response to the energization of both `block indication relays, completing a circuit. at Vits front contact c over contact a of relay 2-4LP to light lamp VWFE or EFE to indicate the traiiic direction established by relay 2-4LP. Relay 2-4LP is controlled by the track, signal and block indication Vrelays and signal lever of the same panel and of the next panel to the right.V When the single track block is vacant and a the head block signals are `at stop, as indicated by the indication relays, if the contacts of relay ,2J-'4LP point to the right as shown they maybe since the right-hand contact c of relay 2-4LP is open, this code also operates the trafiic relay 4LFS .at Station Noi 2 to normal to thereby establish the right-hand end of the block as the entrance end. The operation of relay 2-4LP to its left-hand position, followed by the release of relay ZRFK, prepares a circuit from terminal B at the left-hand contact b of relay 2-4LP over Wire 56, contact CV of. button 2STB, wire 51, back contact d, of relay 5-lLP and' back contacts f of relays ZRFK and 4LFK, whereby the starting relaylsT, at theleft, is energized alongfwith relay 2ST, to transmit a second-code to Station No. I to operate relay ZRFS to reverse over channel 2, which is now energized over the left-hand contact" c of relay 2-4LP, and thereby establish the left-hand end of the block .as the exit end. The block indication relays 2LAK and 4RAK are then -reenergized by indication codes which followv these control codes, thereby energizing relay dLFK to light lamp WFE and to terminate the control of relay IST- by the starting button ZSTB.

Under similar conditions, 'if the contacts'of relay 2-4LP point to the left, they may be operated to the right by placing lever ZSG of the same panel in its right-hand reverse position, thereby releasing relays dLFK, ZLAK andRAK and extinguishing lampWFE. This prepares a circuit for relay 2ST of the adjoining panel at the right, which extends from terminalY BVv at the right-hand` contact b of relay 2-4LP. over contact'd of button ISTB and back contacts g of relays 4RFK and ZLFK, back contact e of. relay 5.-;1LP, and .wire V68, rendering button ISTB eifectiverto initiate the transmission of codes to both stations, whereby relay kZRFS isl operated to normal to establish Station No. las the entrance end of the block, and relay 4LFS to reverse to establish Station No. 2 as the. exit end. These control codes are followed byindic'ation codes which reenergize the vblock indication relays ZLAK and 4RAK; and' thereby energize :relay VZRFK toterminate theV control 'ofrvrelay 2ST-by button ISTB and to light lamp EFE. Y

' Relay 4-2LP, in Fig. 1B, similarly controls the i `tion relayr 2RAK of the adjoining-panel atl the right, which indicatesthe condition of the main trackf blocky'and these relays whlenf released render the starting button for the entrance end of this block, asydetermined by the position v:of relay 4'-2LP, effective to,tra'nsmitvcodes to both ends of the block. Under proper V.conditions relay 4-2LP is operable to the left 'to set up'the rightto-left traic direction by placing lever 2SGof the adjoining panel at the right in its left-hand reverse position, or to the right toV set .upthe leftto-right traflic direction'by placing lever 4SG- of the same panel in its right-hand reverse posi-'- tion. f

Fig. 1A also includes an electric switch lock control lever 5-'ISW and a repeating relay 5-1LP therefor by means of which the trai-lic relays 2RFS and 4LFS may be reversed toestablish both ends of the single track block as exit ends to render the signal line circuitsv available for indicating that the block is unoccupied at ,the location of any hand throw switch in'theblock. By this means the crew of a Vtrain on a side track leading to the main track of the single track block over a hand throw switch may unlock thek switch under proper trac conditions when authorized'to do so by the central -oii'ice operatori.

Fig..1B includes similar arrangements includ# ing'the electric lock control lever SSW and the repeating relay SLP, for controlling the traffic relays dRFS. and ZLFS which govern the reversible line circuit for the block comprising the main track of the double track stretch to provide means for releasing the electric locks of hand ythrow switches located in that block.` i l Each block signal shown in Figsf2A tol 2F is of the searchlight type having a three position mechanism G adapted to indicate caution or proceed when energized in a normal or reverse /direce tion, respectively, and to indicate stop when deen-` ergized, such as is shown in Reissued Letters Pat# ent of the United States No. 14,940, of August 31, 1920, granted to E. J. Blake.V Each mechanism has a circuit controller having front contacts over which a repeating relay such as relay ZRAPC or 22PC may be energized when the signal-indicates caution or proceed to govern .the polarity ofthe current controlling the next signal in the rear,for the same traic direction, and also has back contacts closed only when thefsignal indi- Cates, stop over which a signal indicationrelay such as relay 2RGP or 2LGP may be energized lor Vwhich may be included in the circuit .for an opposing signal as illustrated by mechanism ZIG Each intermediate' signal in the single track block, such las signal 2| or22,.has a directional stick relay 2-ISR or 22SR which vpicks up when a train passes the signal/at caution or proceedto supply current of the proper polarity to the line `circuit for the next signal in the rear to operate The line relay ZRHD, Fg'. 2B; for.' signals ZR'A and v 2RB or the line relay 4LHD,.Fig. 2E, for signals ZLA'. and'ALB', and for energizing the mechanisms for the intermediater signalsV 252 and' 24, or 2I' and 231., and; in. addition provides circuits available at timesff'or: the= release ofi electric switch lo'cks. As shown, the system isV setup forthe leffteto-right traine direction with the traic relay ERES nor-r mali and;` relay 4LFS reversed'.` Mechanism MG, Fig; 2D, is energized in the normal direction in seriesjwith the approachlighting l'relays 23E-R and dRAER: over-lineI wires 3lP and 32., its: circuit including back contact's'bland dt of relays 2'3SR and'23PC for the opposing' signal' 23i, front contacts'. b and d of the-track'relays 26T-R, 4RATR and? 3TH, and of an indication relay 'IWLP for switch' TW; back-1contact d of a stick relay ITES associated with-switch 7W, thereverse contacts banditi of the trafli'c relayLlESf, contacts bandd of' the polel changer relay VIRAPC for signal 4R, and: contacts c of the line relay liLHD and of an'y approach locking relay 4LAS for signals Mechanism 22G, Fig., 2C', is energizedA in the reverse direction in series' with the approach lighting relays- ZIERP and' MER over line wires 'A and 36 extending tothe location of switch SBWl and' over line wires '33 and 34 extending from thatY point to the location of signal 24,V its circuit' including back'cont'acts b and d of' relays II'SR' and ZIPC fontheopposing signal 2|, frontfcontacts b and d"of"tl1e track relays 22TH,

andiZ'STRi, and a front contact aj ofa relay SARK4 adjacent switch"l 513W controlled by these track relays',- front contar-:tsl af, b', c and d of' an indicationrelayv i'rWLP'f forl switches SAW 'and' 5BW,'

anda back contact dof a stick relay STES' associatedl therewith, front contacts l)l and d of relayv 24PC f'or' signal 24, a front contact j of the track relay 24TH, and contacts-closedv by mechanism 23G when signal 23 indicates stop.V The line relay` ZRiI-ID, Fig-1 2B, isenergized reverse in series with the approach lighting relays ZLAER and-v 22ER over line wires 3lr andr` 38, its circuit including the normalv con-tactsjb andl d` of thel traffic relay ZRFS, f-ront contacts bi`- and d of the track relays ITR, ZLA-'I-R and ZIITRQan'd of the relay 22PC for signal'22'f, a iront contact f of the track relay 22TH, and contacts closed by mechanism 2 IG when signal? 2 I- indicates stop.

It follows that signal 2li`I indica-tes caution and signal 2'2 indicatesI proceed, but signals 2BA and 2RB are atbstopbecause their local circuits are open.

The reversible line circuit system for the single. track stretch may be set' up for traffic move'- ments ini the opposite direction, that is to say, from right t0 left, by operating relay ZRFS to its: reverse position and:y relay ALFS to normal, in which; case: mechanism ZI'G' will become S1181- gizedi the'. normal direction and mechanism ESG and-i relay ALFD: in the reverse direction. by the energizati'cn of circuitsssimilar: to thoseV just trace'd, as will'be apparent'ffrom the; drawings.

Traiilc movements over themain track of the double: track pdr-tion`V arev controlled over a retemyprovides vcircuits for the line' relays 4RHD. and: 2li-ID, which govern the. opposing headtblock signals 4R; and 2L for main linevmovements only',-

these signals being/ operable to indicate caution', to. govern train movements; into'the upper pass*- ing track, independently of the-linerelays. As

shown', the reversible line circuit sys-tem for the main track stretch is; set up for; the' left to right traflic direction with the trailic relay IRES norrnal and relay 2LFS reversed. The line relay ARH-D is energized in the` normal' direction in serieswith theapproach lightingV relays ILAER and overx line wires 39 and Mlgiitsfcir-y cuit including' the normal contacts b and' d of' relay ARIES,y a: back: contactx'd` of' a stick relay B'IESI associated withi switch'` 9W; front contacts b andad of an indication relay awLP fori switch 'l 9W, and of the vtrack relays 4LATR and 2RATR1` the` reverse contacts band dof relay 2LFS; con'- tacts be and d of'relay@ 2RAPC. controlled' by signals 2BA and `2RB, back contact c of the opposing line relay` ZLHD and front, contacts c of" a' repeating relay ITP forthe track relay ITR of section IT and of: an approach locking relay ZLAS for signalv 2li., the: contactsv ofk relays: ITP'- and:.2LAS' in this circuit being bridged by'afront i contact df of a switch indication relay IRWP f closed when switch I`Wv is reversed'. It will'Y be n seenY thatv ther control limits: for` signal 4R as established when switch'` 3W"` is normal, extend?l to signal, ZR'A ifu switchv IWTv is reversed, and

through sectionf ITto signalZL if r'switch IW^-is normal.

This lin-ev circuit system is: 'seti up 'for movements. from. right to` lef-thy' operating relay 4RFS to reverse and*A relay ZLES to,` normal in-y which? case relay' ZLHDm'ay: bene'nergized overy similar circuits; including ,thefsame' line wires 39? and 40. l l

Eachi signal i'sjlighted bya lamp E contained in-'its mechanism, which as shown is normally dark, becomingv lighted; to. cause the signal to`v display its indications. when' one or more 'track' sections in approach; to the Vsignal are occupied'.

The lamp ZiI'Effor signal ZI, Fig; 2C, for example, islightedbythe release' or the lighting re-` lay 2 EER, whichaisin series` in thereversible line circuit for mechanisms ZZG and 23G'. The lighting of signals 22,-r 23l and 24' is' controlled bythe similarly arranged' relays.r 22ER, 23ER and ZIIER,

respectively; I'n the caser of the head block sigl nalV 2L Fig. 2B, the circuit for lamp 2IlGlilisv controlled'by a slow releaserepeater relay ZLAAR,

of. the'lighting relay ZLAER, provided in orderto prevent a momentary interruption ofthe lamp circuit during: the reversal ofY thel line polarity i by relay' ZLAPG. The lighting circuits for signalY 4R, and alsoforv signals ZRA and' 4'LA, are` similar to that` i'or signal 2L, while those fori signalsy ZRA` and ELBare; controlledv by the track relays 2RB'I1R' and VliLB'IR. of the corresponding:

l approach sections in theupper passing track.

Each power operated'track switch' such as IW'v is operated byfa snitable'switch machine such as ISMr Fig: 2B: having a. control circuitreversilzvly energized over the polar 'contacts'ia' and b of the."

" corresponding code controlled relay IWS and inver-sible line circuit system' similarly arranged Y for energizationat either enid4 by' thev operation cluding fronti contacts a and b of a switch locking relay I-LR, Fig. 2A, -whichrelay when energizecl indicates that conditions are proper for the operation of' the track switch. The position off` switch; IW is indicated by the normal and refverse switch indication relays INWP and IRWP,v

which are4 energizedaover a. switch circuit conetroller` contact; N or Rt, respectively',` andV overl A pervision,

`contact d of relay" IWSyonly'when the 'switch yis"lock'ed mechanically by the switch machine and is in agreement with the normal or reverseV position f its control relay IWS.Y f Y The'code controlled relays as shown in Fig. `2A

include an auxiliary'relay IWIS, which is operated to normal or/reverse over channels I and 3 in parallel with relay IWS.` The circuits for reIayIWS include a contact d of relay |LR,fso that although the auxiliary relay IWIS is yfree to respond to the switch control elements of each controlcode, the switch control relay IWS responds only ifthe switch is free to be operated at Y the tiIethe codevis received, thereby avoiding switch `control storage and ,the consequent Y operation of the track switch without manual su- `following the 'energization of'V relay ILR. Y

AThe local'circui'ts for the head block signals at Station No. I are manually'governed b'y means lof a'polarV neutral signal control relay ZGR shown in Fig-.-2A, in accordance with a feature of my invention. Relay 2GR is deenergized when relays'2LHS and 2RHS are normal, as shown, and isenergized normal or reversein response to the reversalof relay ZLHS or ZRHS, respectively, over a pick-up circuit including corresponding normal or reverse contacts c of relays IWIS and IWS, and when relay 2GR becomes energized, over a `stick circuit including its own front contact a. 1'

It will be understood that relays IWIS and IWS assume dissimilar positions in response to a code received when relay ILR is released, provided the code includes elements for changing the position of switch IW, since under this condition relay IWIS .will'reslond but ArelaylIWS will remain in f its lastoperated position-corresponding to that of switch IW. It follows thatrelay 2GBI will not Y become energized in response to a code for clearing the signal for a route oVerswitchYIW/which differs from the 'one already established,if such code is received when relay ILR is released and the switch is therebyelectrically lockedv against' operation to the position required for the diiTerent route, and the inadvertent clearing of the signal for the already established Valternative route under this condition is prevented.

The manually controllable relay ZGR, and the line relays ZLHD and 2RHD jointly control a routecircuit network, shownfin Fig. 2B, comprising circuits selected according to the position of switch IW by the relays INWP and IRWP for controlling the route relays 2LH, 2LD, ZRAI-I and ZRBH whichin turn control the head block sig*- nal mechanisms 2LG, 2RAG and ZRBG. The

display of stop indications by the signals is mani- K fested by the energization of signal indication relays ZLCiP` and 2RGP, governing the approach locking stick relays ZLAS and ZRAS,` which'together' with relay ILR serve to electrically inter-y lock the switch and signals in the following manner: Relay'ZLAS, controlled by signal 2L, is released in response tothe energization of the route relay 2LH for that signal and has a back contact eV in thelcircuit formechanism ZLG forsignal 2L, a front contact d in the circuits for relaysZRAl-I and ZRBH controlling the opposing signalsrat the same station, a front contact c, Fig. 2A, in the circuit including line wires 39 and 40 for controlling the opposing signal '4R at the oppositeend of the block, and a front contact b, Fig. 2A, in the vcircuit for the switch locking relay ILR.Y

-Relay`2RAS, controlled by signals 2RA and i 2RB, is released in response to the energizalQD 12 f of the route relay ZRAH or ZRBH, and has a back contact e in the circuits for the mechanisms' ZRAG and ZRBG for these signals, a front conswitch I W.

15 Relays ZRAS and ZLAS are controlled by time measuring apparatus ina Well-known manner,

so as to delay their energization fora suitable time interval following lthe manual restoration of asignal tostop.. 'I'his .apparatus ias shown in Fig. 2B includes a thermal relay ZATE, a stickf:

relay ZATES and a checking relay 2AI'EPcon trolling a circuit including contact f of relay IRWP over which relay 2RAS is energized at the end of a relatively short ,time interval following the return of signal 2RB to stop, provided switch IW is reversed, and these relays together with the similar relays V2BTE,2B'I'ES and ZBTEP provide an appropriately longer time interval at the end of which relay ZRAS or ZLAS becomes ener-r Y Vgized, following the manual return of signal ZRA or 2L to stop, when switch IW is normal. The

Y time measuring'apparatus is set into operation byV the energization of a repeating relay ZASP,

Fig. 2A, controlled by the approach locking relays i and byY the signal 'control relays ZRHS and .Y

ZLHS, and has checking contacts gin circuits con-r trolling the signals to insure that the time'me'as'- uring apparatus is in its normalposition whenV a vsignal is put to stop 'tol initiate its operation, g 40 comprising a back contact b of the thermal relayf.v

such as relay 2ATE inthe circuit `for its checking relay 2ATEP, a front contact a of relay 2ATEP in the circuits for the mechanisms G, and aback contact c of the associated stick relay such asv 'relay ZATES in the circuits for the route relays RH and LH.

y Circuits are also provided for reenergizing the 'approachl locking stick relays automatically, followingV the restoration of the corresponding sig- 5 lLLnals tostop by a passing train, which depend ;t`or.l their `operation uponY the releaseof the ,trackvi relays for two. diii'erent tracksectiona- When a train enters section IT, for example, the track relay ITR releases, deenergizing aslow release;

55.*.;.repeating relay ITP, Fig. 2A. Relay ITR interrupts the signal circuit by opening its front conf tact a, Fig. 2A, to restore the cleared signal to stop and thereby energize the signal indicationv relay ZRGP or2LGP. v'I'he closing of back confygtact a of relay ITR completesV a circuit momentarily over front contact a of relay ITP to restore the operated signal control relay ZRHS or 2LHS` to normal, but without energizing relay ZASP, the circuit for which is open at front contact a 6u' off relay ITR. When the train enters the next section of its route, a portion of the train being in section IT, a circuit is closed over contacts c or relay ITP, Fig. 2B, and of relay ,ZRATR or ZRBTR to pick up relay 2LAS, or over contact d jof relay ITP and contact e of relay 2LATR to pick up relay ZRAS.

V'Ihe local circuits at Station No. 2 are manually controlled by a polar neutral relay 4GB, Fig.

2E, like relay 2GR, and are similar to thoseat v Station' No. I, lexcept that the circuits for the i 1.3i twodirections areinterchanged, but' in other respects; these circuits functionin the same manner... Each hand. throw switch shown' herein, such, as the Switch AW, Fig. 2C; is to be understood. to be2 equipped with a suitable switch stand such.

asis shown in LettersPatent ofthe United Statesl No..25l84,8.70, issued. December 26",A 1939, to Her-A segmentZ heldin its lockingpositionby the bail.

oa padlockv 5.0:, as indicated. diagrammatica-lly herein andas shown in detail'. in theNeubert et al. patent. To unlock: the switch the padlock must first-be. removedby the train crew.. This permits. thesegment 25 tobe: moveda short distance, limitedbythe locking dog 2l, toclose contacts. 464-'31- andrto opencontact; 49to release. an indication relaysuch as the relay 5WLP, Fig.. 2D.

If traicconditions as reflected by the. circuits'- are such that. it is proper tooperate the switch, the'lock. magnet will become energized in. response to the release of relay 5WLP., opening. contact 48 in the circuit for relay EWLP andi lift.- ing-thelocking dog 2:1 to permit segment 25'. to be movedto its full reverse position inv which the switch operating lever 8. is free to be operated, andas explained in` the Neubert et al. patent lever 8.` holds segment 25 reversed as long as the leverfis displaced from its normal position. Each.

hand throw switchisalso` provided with the usual switch 4circuit controller having a. pointA detector contact: N which is closed only when the switch. is locked normal, which, contact is. included. in the: circuit for its indication relay. Y

Relay SWLP has front contacts aand c inthe signal line circuit extending to the left. over line wires 35 and 35, and front contacts IJ and d inthe onerextending totheright over linewires 3.3. andA 34, as hereinbefore pointedout, by means of which the signals 22 and 23 governing approaching trains are heldat stop unless switches SAW and. 5BW are properly locked in the normal. position. The similar relay 1WLP, Fig. 2E?, has. front contactsb-y and cl` in the signal linecircuit extending` to theleft over' line, wires 3| and. 32 controlling;

signal 24, and contact c, Fig. 2F, in the circuiti for the. route relays for signals dLAand 4LB, whichsignals govern movements over switch 1W, andrelay SiWLP, Fig'. 2Fhas similar; contacts. in the-circuits controlling signals 4R and. 2L govern. ing movements over switch 9W.

For movements from` the main track to a side track over a handthrow switch, a circuit for energizing the lock magnet isprepared automatically by the operation of time measuring apparatusl conflprising a thermal. relaysuch', as.Y 5TE Eig.. 22),', together with a stick relay 5TES and a checking; relay STEP; This apparatus functions so as to maintain the switch locked during the passage of a high speed. train, while enabling the crew of a` train vstanding onv the main track` at. the:

Vswitch to release the electric` lock, provided the.

trainapproachesthe switch at a greatly reduced speed and. occupies the approach sectionv for at. least the measured length of time. This apparatus isset into operation by energizing the checking relay such. as relay 5TEP over a circuit including a front contact e of the associated. indication; relay EWLP and back contacts bof-'r-elaysTE.` and ETES; and completed upon the rev (Lil lease of atrackrelay. For: examplerelay STEP is energized' bytheclosing of back contact c o-f an. approach. relay BAR, which relay is released by a', repeating relay 22TP of the track relay 22TR or' g by the. track relay 23TH, when a trainy enters sec.-

tion 22T or 23T. It is to be understood` that. the

time interval measured by the apparatusismade long enough to enforce the proper. speed' reduction in passing from signal 22 to; switch 5BTW or. from signal Z3 to.. switch S-AW, whichever is the greater distance.

The circuit for energizing the lock; magnet7 eAWL or SBWL includes;- front; contact i? of nela'y TES. and ist prepared by the; operation of thes thermal relay through a heating-z and cooling: cycle during which relay TES is.y picked upf, and;

which is terminated when relay:551??'returnstoits;` Y

normal position.. A front contact a of relay SAR; and a back; contact d"` of. relay EFESy are included: in. the-signal line circuitzto prevent a trainimoye ment over the hand throw: switchesY unless theI apparatus is in its normal; condition When.- the train enters the approach section` For movementsfrom; a side track: to the mairr track over a. hand throw switch, authority toire:-v move=the padlock' must bek obtained from thev cen.` tral oice operator. If' the block is unoccupieda andthe authority isgranted, Vhe will reverse the, switch lock lever -lSW or SSW for the b1ock and will then press the associated starting; button, thereby transmitting control.l codesby which: the` tra-nicstick. relays are. reversed. at bothends of the. block. When both traic relays are re.-v versed, the removal of.. padlock.' Fill; by the train` crew releasesthe indication relayWLP and there- 1 by places the` ycorresponding lock. magnet. WL 'unl-1 der the control of the. signal line relayfRHD orNV I I-IDwhen the switch isneartheend:ci"the'block,.

as. illustrated by the circuits for magnets and WL,V or-under the contr-o1 of.' auxiliary line:y

relays;A such; as relays. zWAR and SIZAR'y when the V switch is at an intermediate point, as illustra-ted by the' circuits' for magnets AWL and rBwl-l; thereby permitting the lock to be released ati once und-.erthe proper trailic conditions.

Having. now described'. the various elements o@ the system of my invention, Ifshall now describe its operation under: difieren-t conditions.

I shall. -rst assume that the system is in. the conditionl shown in the drawings; setup for-title-y left-tright. traf'c direction with theftrack-gun occupiedt and all; head. block signals at stop.

To: clear the entering head block sign-a1 2BA fcrthe single track block, the operator irstmoves.y

' lever'y 'SGfto its rightfhand; reverse-position, com# pleti-ng a circuit from terminal B at the iront Contact; cof relay ARAK, Fig; IA, over front: conF tact e of .relay ZLAK, hack contacts d et relaysA ETI-K andl 2l'-\,fl'.{,` wire 54:, back: coi-itactsy b. oiA re lays ELI-Ils'. and BTK, wire 5.2, contact cof lever ZSG through the upper lwinding of relay Z-ALP to terminal C, energizingL relay 2.-4LP in the reverse direction', asy shown'. Lampl EFE. is lighted over the circuit extendingA from terminal @Bf atf contact c. of relay Z-RFK andthe reversecontactd .of`- relay Z-lLP through lamp. EFE to. terminal C.. v

The, operator then presses, button ESTE. which with the leftrto-Tight traiiic direction already set up, as shown, energizes relay4 !STonl'ytransmit ting a controlcode to Station No'. I' by'which'relays Oi'S and. ID are energized; so that the Code controlled relays ZRFS and' ZLHS, Fig'. 2A, are energized normal; their respective channels 2`and;

5 being open, and relay ZRHSl is operated' to reversedue to energy being supplied from termi? nal B to channel lover contact d o'f` relayOIS and the right-hand contact a of lever ZSG. Re-

lay IWIS will be operated to normal over channel I, and also relay IWS, provided 'switch' IW 'is not locked. Relay ELFS is energized in the rerthe reverse direction over the circuit extending from terminal B at the normal contact a of relay ZLI-IS over the reverse contact b of relay ZRHS,

ynormal contacts c of relays IWIS and IWS through relay ZGR and over the reverse contact dof relay ZRHS and the normal contact b of relay ZLHS to terminal C. Relay ZGR completes its stick circuit, and also'closes its right-hand polar contact c which completes a circuit for the route relay ZRAH, extending from terminal B at front contact a of relay ITR, Fig. 2A, over `wire 1|,.contacts c of relays ZATES and ZBTES, contacts b and c of relay ZGR, contact'd of relay 2LAS,Ycontact a'of relay ZRHDVback contact a ofr relay IRWP and front contact a of relay INWP, back/contact d of relay 2RBH through relay ZRAH to terminal C.

Relay ZRAH picks up, and .by opening its contact c releases the approach locking relay ZRAS, which in turn by opening its contact b, Fig. 2A, releases the switch locking relay ILR, thereby locking relay IWS and the switch machinev ISM in th'enormal position and completing the circuit for mechanism' 'ZRAG extendingrfrom terminal B'over contacts a of relays ZATEP .and ZBTEP, vcontact c Vof relay ILR, contact e of relay ZRAS, reverse contact b ofV relay ZRHD, front contact a of relay ZRAH, wire I2, mechanism ZRAG, wire 13,1front contact b ofvrelay ZRAH to'terminaLC over the reverse contact d oirelay ZRHD, thereby energizing mechanism 2RAG in the reverse direction. j

vWhen mechanism ZRAG becomes energized, its circuit controller contacts shift to energize the pole changer relay ZRAPC, and to disconnect terminal B from wire 'I4 to release the signal indication relay ZRGP. Relay ZRAPC reverses the polarity of the current supplied to the line wires 39'and djthereby reversing relay llRHD,V if energized, and conditioning the next signal 4R`in the rear of signal ZRA to indicate proceed, provided switch 3W is normal. Relay ZRGP', by'releasing, kinitiates an indication code..in which "channel I5 is energized over itsrback contact c to pick up relay ZRHK, Fig. 1A, and relay ZRHK, by closing its front contact c, lights lamp ZRE to indicate that signal 2RA has been cleared, and by opening its back contact d locks relay 2--4LP reversed.

When the train approaching signal ZRA from the left enters the approach section 4LAT, Fig. 2F,` relay IILATR releases to open the line circuit including wires 39 and 40, releasing relays IIRHD,

4LAER and relay ZRAER and also the repeating relays IILAAR and ZRAAR, thereby lighting lamp 2RAE to cause signal 2RA to display its proceed indication, also lighting lamp dLAE to cause the opposing signal vlLA .to display astop indication. IV shall next assume that the apparatus has been restored tothe conditionshownin the drawings and that the operator Wishes to clear signal ZRB in place of signal 2RA. Y

- To clear signal 2RB, the operator reverses'lever ISW, moves lever 2SG to the right and then press-v es button ISTB to transmit a control code to Station No. I. The operationof leverZSG energizes:

relay 2-4LP in thevreverse direction as in the Y, preceding example, but in the code Ynow transmitted, channel I is open, and channel 3Yclosed' over the reverse contact a of lever ISW, reversing' relays IWIS andV IWS. The closing of the reverse contacts a and b of relay I WS, Fig. 2B, initiates the operation of switch IW to reverse'and the'V reversal 0f contact d of relay IWS releases relay INWP and preparesa `circuit forfrelay IRWP,`

which relay becomes energized when switch 'IW-is fully reversed. Channels 2 and 5 are open, and channels and' closed, as in the preceding example. Relay ZRHS reverses, and 'relay ZGR;

becomes energized in the reverse direction over'y the reversecontacts c of relays IWIS and.k IWS,I

but relay 2RM-I remains released because its circuit is open at the front contact a of relay INWP.

Relay yL'RBi-I becomes energized When relay I RWP picks up over a branch of the circuit for relay 2RAH already traced, extending from back contact a of relay INWP over front contact a of relay IRWP, back Contact d of relay 2RAH and ugh relay back contact a of lrelay ZRAPC' thro 2RBH to terminal C.

Relay ERBI-I lpicks up, Vopening .its contact c to release relay 2RAS, which releases relay ILR to lock relay IWS andV switch machine ISM in the reverse position and to'compl'ete a circuit'ovey wires l5 and 16 at the frontfcontacts a Vand boi?Y .relayERBH to energize mechanism ZRBG in"the,

normal or reverse directioncorrespondingA tothe position of relay ZRHD, disconnectingfterminal B from wire 'I4 to releaserelay ZRGP to initiate an indication code as inthe caseof signalvZRA above described. Signal VZRB becomesV lighted upon the closing of backcontact d of relay ZRBTR when an'approa'ching train enters section ZRBT.

I shall next assume'that the operator desires to clear the leaving signal 4R at the vright-hand end of the block, to permit the rtrain to pass through the double track stretchat the right.

' For a movement over the main track, the operator will move lever ASG to the right, with` lever 3SWV normal, and pressv the starting button ZSTB.' Lever @SG inV its right-hand position completes a' circuit from terminal B at the front contact e of relay ERAK, Fig. 1B, overv back contacts d of` relays STK and llRHK, wire BI, back contactsb of relays 2LHK and ITK, Wire 62,"contacts b of levers SSW and SG through the upper WindingV Vof relay 4,-'2LP to terminal y C, energizing relay 4%2LP reverse, as shown.

f With the left-to-ri'ght trahie dir set up, energizes relay 2ST only, transmitting a control code to Station No. 2 in which channel I is energized over contacts a of lever SSW and relay 02S,

ection already channel 2 is energized over contact b of relay 02S, wire 63 and the reverse contacte of relay 2-4LP, Y channels 3, 4 and 5 are open and channel 'I en- Y ergized over contact a of lever 4SG and contact d of relay 02S, so that relays 3WIS,3WS, 4RFS and @LHS are operated to` normal and relays LFS'and RHS to reverse. Relay RHS energizes relay 4GB, reverse, and relay AGR completes a circuit for the route relay IIRH, Fig.'2F, extending from terminal B at contact a of relay STR, Fig. Y

2E, over wire BI, contacts c of reIaysfIATES and ABTES, contacts b and c of relay IIGR, contactd of relayLAS, front contact c of relayBNWP, contact c of relay 9WLP, contact a of relay 4RI-ID, i

as sho-wn, the operation of button ZSTB' signal "ZR'Aas hereinbefore-r pointed` out.' When relay SLR, releases; theclosing1 'off itsf contacte? completes a circuit for-mechanism 4RGfromterminaluB" over-contacts aof. relays dAT-EPll and 4BTEP, contact c of Arelayf3LR, contacte of re'layrk 4RAS, extending through' mechanism RG to terminal C over contacts a and b of relays-4-R;D"

andARI-Il andiwires '8lr and 885 Ihe mechanism' IIRGbecomesenergizednormalf or reverselto correspond with the' position.of'-'re' lay IIR'HD, energizing relay llR'AP'C over vcontact f dfiofrelay 3NWP, and' disconnectirr'gfterminaliB` from Wire -Blttourelease the indication relayJ4RGP suppliedf over line"'wiresll3l and '132 tof-mechanism' MG; which accordingly reverses-Itocondition the f next sif,fr-1a,l-i."ll,A in the rear: of' signallRgto indi-if cate proceed. Relay R'GP'upon releasinginiii tiates. an' indic'zation-fcode` energizirfigY channel `I 5`at its 'contactcI to 'piclrlupv relay! llRHKffFig. 1Bg therebylightinglamp AlREi The opening ohback reversed.`

When the-train approachingl from' they left'l enters-the single i track blc'cl,l tlieI -releaseiof re'-' -f lay ITR opens the circuit `rinclufdiiig'line fw'iefsif 31 and 38T; releasing theseries lightingrelay ZZER comes lighted to indicate caution or-proceed}`when lightsf ITKE, BKEfand STKE; rel'ayr' 2-4LP 'being held-1-deenergiz'ed1"ir1 -its reverse position by the release of the indicationrelays' whichV control these'lampvs. Similarly, the movement of the trainlthrough the main 'track ofthe double track! portion is indicated by'the lighting of'lamps 3TKE, ZRAE and ITKE controlled by the indication lfrelays Vwhich hold relay 4-.2LPJ reversed, While if vthe train enters the side track lamp GLAE *i is lighted inplace of slamp' 2R`AE.`

I shall now describe the yoperation of the sysL temhunderl conditions involving'Y the reversal of thetrafiicdirection, assumingfas before that the apparatus-'isset up for-the leitete-right directionwithy 'the rbflock'zunoccupied' andv al1 lfieadfbloclrl-- signalslat stop'.v

To 'clearf the entering head block signal llLAfor'v the'sngletrack block-under this conditiongv the operator moves lever 4SG to the left, with lever 38W normal, and then presses the starting buty ITK? and 'ZRHK, wire" 5I contacts b--loffy I relays Y the 'train enterssectionf` 24T-"to openithe icireuit' 4 lease relays ISRAER and R'AAR' side track; the operatorY reverses lever'` 35W,"

moves lever'ASG to the rightfand thenpressesbutton" 2STB"13O transmita* '00de' n "Whtlilr'Only-A channels 2,` 3` 'and "1* 'are energizedreversingl 're-- mal'directin te irldicatecautioni RlayIRAPC remains rele'asedf' because contact dfof relay`- SNWP in fits circuit isfopen, consequently the next' signalfZll 'inl the rear is Valsoconditioned lto indicate caution;

It is deemed unnecessaryftoy tracetliemove-l ment'of the train step by step through' the `successive tblock sectionsjinview of theldescriptionof the various elements of thesyste'malready pre--v sented.` It is to be Ynoted,lhovvever, that the pas'-y sage of fthe train l'through the-single track blockvv is indiatedfbytli'e lighting -ofthe track-`di`agraml f relays `ZIAKS and ARAKI; l andL lopeni'ng the Stick circuit frlrelayifZRFK at its right-han contact' b'g causingv relay LZRFK to release' after 'a' short 3' time tcpreparefnew1stick-:'circnitsboveri its flcaell Contact dfor; lfiolrlinggf'frel'aysand 4RIA`lv energized: 'whenithese ilrelays yare next; picked iup' over `cl'i'annel'iv12.3l RelaYfIZ'-LP is nowffree'fft be operated back and forth at the will off'tljielA operatorj" by? closingcontacts cfofflevers'Z'SG and SSG '.'alternately;' diet the" connection of Wires 52 'and-51 to terminali-Hoverbackcontacts' eof relays2I1l`AK,LFKand'iZRFK.l They oper#y atoms therefore fnowrfable'r t'rirestoref'tne original direction of traino,Vvl or? ithe'- case of` a vfault,-to maherepea'ted attemptsto reverse the` tra'flc" direction, if? heso' de'sire's.-k Assuming thatthe left-hand contacts' ofi-relay" ZLALP 'rem'ainiclosed", relay ZST- becomes energizedin responsefto the operation .of 'button' 'T to i transmit" a, control i, codetofStationf'No. 2 whichfonlylbhannelsl" and 5 are energized to operate relays SWIS," 3WS' 4I1FS `f'a,nd`-"IR,IIS` lto normal; and-'to' reverse r`relay Atthefsame time'frelay I ST becomes en'- ergiz'ed' .'irr response" `to this operation'f of f button? ZSTB over "a circuitv extending S` from :terminal l Bvat the lefthand 4Contact?) of 'relay Zi-IILP, VWire'-` 5`6;zconta;ct"cof button ZSTB, Wire 51, contact Tdi" of relay "5l-TWP; contactsf of"relays`2R^FK-` and 4LFK'throughfrelay IST to terminal C', to=`tr`ans 'mit` a second. code to? Station No.1V l, in 'which channel' 2 -is'V energized overthe left' -han'dvr contactc of Trelay'l 2-"4ILP," tocre'verse" relay :ZRFS

At Station No," 2'the restoration oi'relay '4LF`Sf' tomormal: disconnects V'terminals B and C"A from.V the `,rigl'lt'll'rand''end of .fthe yreversible-line circuit' systemand` connects relay 4LHD'tothe line vvir'es VY 3| and 32', releasing"mechanisml 24Gfan`d frelay MPC.l Relay'24`P`Cshift's the connections of line Wires` 35"and"36'from terminals fB'L and C' ofthe adjacent "source to the 'Winding'7 of 'mechanism y ESG; releasing mechanism 22Gr` and "relay ZZP'C. Relay 22 PC shifts the'connections of `line Wires S'Iand 38 from term-inalsB/and'Cof thesource at its location tothe Winding of 'mechanism 2 IG? and -the operatin of relay -ZRF'Stofnormal shifts f circuits, and since the coding system is arranged to transmit indication codes following the two control codes, as already mentioned, relays lZL'AK and 4RAK are'reenergized over channel I2` by indication codes transmitted from Stations No. I and No. 2, respectively, completing a -circuit over their front contacts b to pick up relay 4LFK to prevent the response of relay. IST to subsequent operations of button ,2STB, and to light lamp WTE.'

Relay AGR becomes energized in the normal `directionin response to the reversal of relay 4LHS, and completes local circuits for clearing signal 4LA similar to those for. signal 2RA already traced, as will be apparent from the drawings. To clear signal 4LB when the left-t'o-rightV direction is set up, the block unoccupied and the head`V block signals `at stop, the operator reverses I lever 3SW, moves lever-ASG to the left and presses Vbutton 2STB, Vresulting in a reversal of trafiicdirection as described in connection withl signal y IILA, and in the operation of switch 3W to reverse and the energization `of mechanism ALBG in the normal direction to condition signal 4LB to indicate caution, over circuits similar to those already described in connection with the corresponding signal ,2RB, consequently a step by step description 'of these operations is deemed unnec essary.

vConsidering now the apparatus for thev double track stretch under conditions involving reversal of the traiiic direction, it will be assumed that signal 2L is to be cleared with switch IW normal, for a train approaching from the right and that signal 4R has been cleared with switch 3W reversed for a train lapproaching from the leftV i which is to enter the siding to permit the op# posing train to pass on the main track. i

To clear signal 2L, assuming sections IT; ZRAT and 4LAT to be unoccupied With the left-to-right traffic -`direction set up as shown, the operator` moves lever ZSG to the left with lever I SW normal and presses button ISTB. Since switch 3W stands reversed, its reverse indication relay SRWK is now energized, fand the closing of contact b of lever ZSG completes a circuit from terminal B at front lcontact e of relay ZRAK, Fig. 1B, over front contact d of relay 3RWK, wire 6I, back contacts b of relays ZLHK and ITK, contacts b of levers ISW and 2SG,Wire 64 through the lower Winding Vof relay 4-2LP to terminal C. Relay 4-2LP closes its left-hand contacts, disconnectf ing terminal B at its contact cl from wire I55'to` release relay 2RAK.- The opening of the righthand contact b of relay 4-2LP deenergizes relay 4RFK, .which relay releases rafter a brief pe-v riod. Relay d-ZLP is now free to be operated back and forth at the will ofthe operator like relay 2-4LP under similarconditions, but assuming that the left-hand contacts of relay 4-2LP remain closed, relay IST becomes energized in response to the operation of button I STB to transmit a control code to Station No, i at the right-hand end of the block in which channels I and 5 are energized over the left-hand con.

tacts a of levers ISW and 2SC, respectivelyg and channel 2 as well, assuming the left-hand con-` tacts of relay 2 4LP to be closed, so thatrelays IWIS, IWS, rZLFS and 4RHS are energized normal and relays ZRFS andl 2LIIS are energized reverse. At the same time, relay 2ST of the adjoining panel at the left is energized over the circuit from terminal B at the left-hand contact b of relayA-ZLP, Wire 6B, contacts c of lever-v ISW and of button I STB, Wire yIi'I, contact 'd of relay SLP, contacts f of relays 2LFK and RFK through relay 2ST to terminal C, to transmit ;a

secondV code to StationvNo. 2 at the left-hand end ofthe block in which channel 4 is energized over the left-hand contact c of relay l-ZLP to reverse relay 4RFS. 'f

At station No. l, the restoration of relay :LFS v to normal disconnects terminals B and C from the right-hand end of the line circuit including the line wires 39 and 40 and connects relay ZLHD thereto, releasing relays 4RHD and the lighting relays in series therewith. Theoperation of relay 4RFS to reverse shifts the connections of Y come energized,V relay 'ZRAER' energizing relay I ZRAAR to initiate an'indication code at Station No. I in which channel I4 is energized to pick up relay ZRAK. Relay ZLFK, Fig. 1B, becomesenergized over contact b of relay ZRAK to prevent the response of relay 2ST to subsequent 0D- eration of buttonrlSTBff v v Relay yZGR becomes energized in the normal direction in response to the reversal of relay 2LHS and completes local circuits for conditioning signal 2L to indicate caution, similar to those already described in connection with the corresponding signal 4R.

Assuming next that the train -rnoving fromv right to left is to take the siding and that the one-moving from left to right is'to passon the main track, and that the line relay 4RHD controlling signal IIR is energized over the circuit Y extending to terminal B over contacts c of relays ITP and ZLAS, in Fig. 2A. Ifv the operator now reverses lever ISW and moves leverv ZSG to the left, the circuit traced above including wires 6I and E4 and contact b of lever 2SG for operating relay 4-2LP to its left-hand position is open at contact b of lever ISW,-and if'signal 4R has been cleared, also at contact d of relay 4RHK. relay 4-2LP remains reversed and relay RFK remains energized and the circuit includingwires B6 and 61 by Which'button ISTB controls relay 2ST is held open at contact b of relay 42LP, at contact c of lever I SW, and at contact f of relay dRFK. Under the Yconditions described, therefore, the operation of button ISTB results in the transmission of a code to Station No. I only, this being sufcient to eiect the clearing of signal 2L for a movement into the side track by the operation of circuits similar to those already traced in detail for the opposing signal 4R..

Returning now to a consideration of the single track block, and assuming the apparatus tobe set up for the rlght-to-left direction .withY the `track unoccupied and all head block signals at stop when the operator moves lever 2SG to the right and presses the starting button ISTB to transmit a code to Station No. I, for clearing signal 2RA or ZRB, as hereinbefore described. Under these conditions the closing of the rightv hand contact c of lever zSGcornpletes a circuit- 211 over.I wiresg l 1ancl.;52 ftozoperatexrelay llLP tot reverse; releasingrelay' llliflFKsoit-,hatwhen button; I STB y;is:' operate'd.: a :circuit Will. be 1: closedsfromc terminal BratLthe rightf'handncontact-'b ,ofjre'laysl cuits for vfclearing@y signal 'ZR'A or-:ZRB'I Tli'eflineicircuit `for themaintrack Ilolock ot the doublezt'rack :stretchf-mayzbe similarlyrestoredv to fi thelleft-'ito-right direction by: operating lever IISG?? tozthe/Irightiwith"leverY SSW? in 'its normal posi-V 25;

tion to' zcomplete-A aA circuit over wires y-l IV and i 6211i andi contacts :o lofthese levers to operate relay 4- f--2F4Rrtoy the.l right; releasingfrelay'LFKf, and rendering button ZS'IB'effectiive vto energize re-flayvl S'Iifofitlieadjoiningpanel at the right o'ver 3o thecircuitincludi'ng: wire f5 8.

It?A Will'- be.: understood fth'at the resultingfindica-y tiorr codes/'causefrelay ZRFKfor-ARFK to vbecome energized',4 interrupting the connectionoverffwire 68 'orf 58; and that 2th`e -f starting "button for the 35 entrance end of theiblock'fis" `only-1temporarily'- effective to inititerthe transmissioni-of 'codes to boizl'iends` Ii Asha-ll 'now-J describe the "operation'o the vsystem under-'fconditins involving the operation ofAf 40 the hand throwsW-itches; assumingthat'the-apf paratus-"isv sctfiupefor the '-lefftto-'right directionoftraicfmovement' as shown.l

Assuming fir'stfthat a train isapproaching sig-3 over switch" SAW or Y EBWi Whenfv theeapproach' ing itraiifl.#entersl section 22, the release offthe' trackrelayl 22TH; completes a-circuitfmomentarilyl' from terminal Bat its 'back`A contact e 'overfront contact/'a loffrelay 22PC through relay;;22SRfto-50 terminal-2C sowthat relayf22SR picks -up,;est ab' lishin'g 'a sticlrcircuit' at lLitsown front contacta; The-opening n'of ifrontcontacts aV and vc "ofrrel ay i 22i'I'R'-causes the frepeatingf'relay- 22-I'P,Fi'g, A 2D;

tal-release yand to open atsweontacts a andremo S55 release relay rSARatthe locatiorr'of` switch'EBW', thereby completing a circuitk from terminal'B" at front Contact e of lfrelay--5WI.|Poverbaclcontact c of 'relay' 5AR`fandback-'contactsb of `'relays STE and STES through relay 5TEP to terminaliCl' 60 Relay"4 5TEP becomes 1 energized. to complete a stick circuit at, its` ovm front YContact.` b` and;to close its contact c to energize the thermalrela'y STES* At the iend of a predetermined heatingpegize-relay-f5TES, which picks iupl ,and j comple'tes, a stick circuit at its own frontcontactla comprising Ia'loianch of -th'e circuitor re1a`y.,5TEP. Relay STE is deenergized bytheopeningfof.back contact vc of relay lSTES and returns toits norma1 70 position, closing,its contactib1atthe endlof, a predetermined cooling period.

The. switch indication relay SWLB is normally energizedover. aicircuit including, the, 1ine iwiies 7 4 l''andv '42' from terminals Band C of r the sorcejV 75 atjzthefflocation: oniswitcht SAW, `and isgreleased iifflfierntlie;trainl crewremoyes padloclnuoii'eithen' switch SAWzf'or; 5BW"bysthe opening of'tlie corg-fresponding::contact; i4 9,; and the. 4release of relay SWLB comple'tesv new; :stick circuits: vf or f relays i S'IER-and; ETES; over; front, Contact, ai :of relayfj: 5TEP; extending;A to. terminal :B' at 'back :Contact: eiofzrelayrWLP.' f I The time measuring :operation therefore con-e tinuesziffinotfialreaidyl completed;.the: c1'osing: o'fi contactgb.foizjrelaytTEf-at zthe: end :offits icoolei ingiperiod zcomplietingy `arrirciiitl fon; the: selectedi vlock magnet' SAWL yor EBWL over front Contact.:`

b'rof krelay .fE'I'ESLaand-.zcontacts 14 6.-;-4'lj tlie `circuit f also: ',includingtimthezcasei ofJ-fmagnetlAWL; the? normalandzlocke'dbyreplacing padlock 50; j releases the'flock magnetto close-contactitlgand* therebyreerrergizes-.the indication relay E5WLPto c1ear.:signai f22fforathefollowing train. '5

The time` 'measuring apparatus associated with` switchesilW :and19W?functions:similarlyI Vthat for' switch IWfbeingisetfinto operationwhen a train enters section ARAT 'OrcSTand "that *for 'switch' f 9W- wh'enatrain enters *sectionALATg lonfa'unovementfzfrom` aside track-to the main" tracksover 7'a handl throw i' switch, Y the 'train-.fcrew must, request ith operator by telephone ori-other- Wiseetoiauthorizefthe imovem'entY Iff'trafc 'conaf ditions -faredavorable andthe operatorl consents -1 tofassmovement'" from aaf side 'track loverfa f hand throw isW-itch) into'lith'eisingle ltraclr'block? he Will-f roven eleven-'i S-e-TSWZ and .pressifbuttom lS'IBVIA lA completing 'ai circuit'ffrorn terminali Bi Tat Contact f yover tlrecircnit exten'ding-frornfterminal Bover-v channel 2 :isyenergized: over contact croi relay f' 5-1LP, Wire 59, contact e of lei/erJSGiandoon'- tact bfof relay I02Stol `reverse. relayV 4LFS. Conta'ct 'c fof..fthedirectional reljy 2il`4LP providesafvv second: connectionrsto 'channel 2 iat g one panel` or" the other over which the traiic relay at the exit@ endilorthe a block;y as indicated by-fthe position-'of relayi=2^-4LP;,="haswalreadyr beenl reversed,` l Ttief circuits-l1 establishedzfhy- I the switch lock' f lever-'f therefore are effective tofrevers'ethe traili'c relay at :that fend' of :the-blocki at-wliiclifitisnot "-alrleavzlyv reversed,; for1"e'rther `directionfoff'traii.l .Un'de'rc this -L condition signals 2 if fand '-2 Mare conditionedtonindicate cautidnfand signals 22'and` 23-'arelatfi stops- Y Y Y I thereby@ energizing H relay l-1li?? and y" left and relay SEAR to line wires 33 and'3lV ex- VVSince relay STES Apicks up first, relay STEis not energized and the circuit for the lock magnet'- SBWL, which'in this instance extends from `ter-- Assuming firstA that the-.train is on mesme.- track at switch SBW, the release of the indication relay SWLP by the train crew'connects relayV SWAP. to lline wires 35 and 36 extending to the tendingto the right, and if theentire blockis unoccupied, andthe 'entering head'iblock signals are at stop with their approach'lo'cking `relays 2RAS and ALAS yenergized,'re1ays SWAR` and l' SEAR pick up to complete a 'pick-'upcircuit :for

relay-STES over their fro'ntcontactsv a, extend- B. at*- back "contact e of relay i ing to' "terminal SWLP.

.Relay 4S'I'EPpi'cksup over contact a of relay STES, completing stick circuits vat its own-,contact a for holding relays STEP and STESenergized.

' minalB latbackfcontacte of relay SWLP over f STEP picks up front contacts a and b of relay STEP, back connal 2| will indicateV caution an'drsignal 23-willindicate-proceed, and relay 4LHD will thenbejcome energized, provided the entire block is unoccupied, but signals 4LA and IILBv are held at stop, because the circuit for their route relays? lILAI-I and ALBH is open at contact c-of "relay JWLP. Relay ITES becomes energized overthey Y circuitfrom terminal B at back contact e of relay tact b of relaySTE, front contact b oi` relay STES and contacts' 3S-41,' is completed when relay atonce.V l.. Y, 'Ihelock for switch SBW or .SAW may also'. be

V released vfollowing the passage of 'a through train through section 23T.into'section 24T,`in which case relayV 24SRpicksup when the throughtrain passes signal.24 to-'supplycurrent to linewires 33' and 34,' thereby energizing relay SEAR as soon V as the' train` vacates jsection-l 23T, relay i SWAR i being energized as in the preceding example.

When the vtrain movement fromthe sidetrack tothe main line via switch SBW is completed and the -operator hasbeen advised by the train crew that the switch is again locked normal soas tol 'are both energizedin response to the operation of button ISTB, whereupon relay S-TLP is released. This' operation is eiective therefore to transmit codesto both stations vbut since relay S-'ILP releases before' they are transmitted, channel 2 is energized in the code transmitted sothat the lock may: be releasedV 'IWLP, the reverse contact a of relay dLFS', front -contact f-,of relay 4LAS andy front contactv e of relay 4LHD to complete the circuit for lock magnet'IWL including front contact b of relay .'ITES;

Contact f of Vrelay ILAS provides approach locking protection' for switch 'IWL corresponding to that provided. by contact b of relay 4LAS, *foraI switch 3W.

When the right-to-left direction Ais set up, switch 1W may be unlocked in the rea-r oI a train which has passed signal 23 to energize relay 23SR or 23PC, as will be readily seen. For a movement into the main track of the double track block over a hand throw switch such as 9W, the operator reverses lever SSW to energize relay SLP, and presses the startingzbutton 2STB, completing a, circuit over contact Vb' of;

, buttOnZSTB, contact c of relay SLP and wire S8 tothe exit end of the block only, according to the position of relay `2-4LP, and thereby restores the line circuits to `their normal condition.

When the train which entered 'the blockvia switch SBW reversed passes signal 24 at clear or caution, relay 24SR picksup to supply current to the line circuit in the rear to condition signal 22 to indicate caution and to permit the entering head block signal to be manually cleared, as will be readily apparent. i f i It will also be clear that when the right-to-left direction is set up, trainmovements similar Vto those just described may be made in that direction.

,Assuming now that-the train is on the side track at switch 1W, Fig. 2E, and that the operator reverses both'traic relays ZRFS and 4L-FS as -above described. When relay 1WLP is released by the train crew, the dropping oi its contacts b and d disconnects terminals B and C from line wires 3l and 32 and connects relay 4LI-ID thereto, restoring signals 24 and 22 .to stop, and since the operator h'as reversed relay ERES, sigto pick up relay IST of the adjoining panel at the f right, along with relay 2ST, to transmit lcodes to1 both ends of the main track block t0 energize relays 4RFS and ZLFSY reverse, and when lever SSW Yis subsequently restored to normal, relay SLP is held energized overa stick circuit including wire 'I0 until 'a second code is Vtransmitted to set f up the traiic direction corresponding tothe position of relay 4-2LP,-these operations being similar to those already described.v Y

. When relay-SWLP is released by the train crew, the dropping of its contacts b and d causes relay 4RHD to become energized, provided the portion of the main track block to the right -of section 3T isy unoccupied, signal 4R, being held at stop, 'if switch 3W is normal, by the opening of contacte of relay SWLP in th'e circuit for its route relay IRI-I. If section 3T at the left-hand end of the block is also unoccupied, or switch 3W reversed, the energization of, relay IIRHD completes a vcircuit for relay STES` extending from terminal B at back contact e of relay 9WLP over the reverse contact a of relay 4RFS and over contacts f of relays vSRAS and relay 3TR or over contact g of relay SRWP, and contact d of relay 4RI-ID, and

relay STES then picks up to prepare the cireuit for magnetQWL. Contact f of relaydRAS provides approach locking protection following the return of'signaNR manuallyto stop after ,having beenvcleared, with switch 3W normal.

It will be seen that in each diierent arrangement shown, the lock magnet circuit is completed only when the traic relays are reversed at both endsof the block.

Although I haveherein shown and described only one formel railway traiic controlling apparatus embodying my invention, it is understood that various changes andvmodiiications may be made therein within the scope of the appended claims without departing from the spirit and scope of my invention. v

Having thus described my invention, what I claim is:

1. `Railway traiiic controllingY apparatus com prising, a signal at each end of a stretch of railway track for governing trac movements into.y

the stretch, a signalV control relay and a trailic relay at each signal location, a system of'reversible signal ,circuits controlled jointly by said traic relays in selected postionsvand by trac 'V 

